HomeMy WebLinkAboutSDP202000063 Calculations 2020-10-05SHIMP ENGINEERING, P.C.
Design Focused Engineering
October 5, 2020
County of Albemarle
Department of Community Development
401 McIntire Road
Charlottesville, VA 22902
Regarding: HTC Area C Townhomes: Block 11 & Block III
Stormwater Management Plan
Dear Reviewer,
Enclosed are the calculations and details relating to stormwater quantity and quality for the
proposed development of the HTC Area C Townhomes at the Hollymead Town Center. Stormwater
management on site is grandfathered as per 4VAC50-60-48. All runoff shall be routed through new
culverts and channels into the existing sediment forebays into the regional stormwater detention pond.
Per the approved ZMA201700005, regional stormwater facilities are provided. Regional
stormwater basin in TMP 3213-A to serves Block III (TMP 32-41K1) and regional basin in Block I (TMP
32-41133) to serves Block II (TMP 32-41J). Per correspondence from Albemarle County, the stormwater
pond for the Hollymead PDMC was designed for a maximum impervious cover of 85% to meet the
requirements for stormwater quality and quantity.
As shown on the included Open Space Exhibit, the new development of TMP 32-41K1 has an
impervious cover of 24.6%, and the new development of TMP 32-41J has an impervious cover of 64.4%.
The proposed plan meets the stormwater design regulations for both of these parcels.
If you have any questions or concerns about these revisions, please feel free to contact me at
steohanie@shimp-en ingeeringcomorbyphoneat434-227-5140.
Regards,
Stephanie Paul
Shimp Engineering, P.C.
SHIMP ENGINEERING, P.C.
Design Focused Engineering
Contents:
Block II
Open Space Exhibit
Inlets Drainage Area Map
Structure Drainage Area Summary
VDOT LD-204
VDOT LD-229
Block III
Open Space Exhibit
Inlets Drainage Area Map
Structure Drainage Area Summary
VDOT LD-204
VDOT LD-229
Independent Reports:
Excerpt from NRCS Soils Report
NOAA Precipitation Report
SHIMP ENGINEERING, P.C.
Design Focused Engineering
Block II
Open Space Exhibit
Inlets Drainage Area Map
Structure Drainage Area Summary
VDOT LD-204
VDOT LD-229
ow
AMPEYMEERIN6 P.C.
ENGa'EEM-MADPLANNa'G-PRGPECTMANrIGMAT
HTC AREA C Townhomes BLOCK II
OPEN SPACE EXHIBIT
REVISION DATE: 10/05/2020
LEGEND
IMPERVIOUS ON SITE
TURF ON SITE
AREA CALCULATION
DISCRIPTION SF AC
IMPERVIOUS 110,299.68 2.53 64.4
TURF 60,995.57 1.40 35.6
TOTAL 171,295.25 3.93 100.0
STORM MASTER PLAN ALLOWABLE
IMPERVIOUS = 85%
1'=50'
150
I \
II II \
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v
590--
588—
cgs
SIIIMPENGINEERIN6 P.C.
LNGa'EEM-MADPLANNa'G-PROWTHANrIGMAT
s''
e
B An' _
HTC AREA C Townhomes BLOCK II
Inlets Drainage Area Map
REVISION DATE: 10/05/2020
r s
r
60
NY
Scale:
1'=60'
LEGEND
INLET DRAINAGE AREA
YARD DRAIN DRAINAGE
AREA DIVIDE
TURF AREA
M
HTC AREA C TOWNHOMES BLOCK 2
Inlet Drainage Area Summary
Impervious C 10.9
Pervious C 10.3
To Inlet Area Impervious Turf C A
A8-DI-7 17,001 9,399 7,602 0.63 0.39
A6-D1-2A 38,914 29,593 9,321 0.76 0.89
A5-DI-7 15,410 5,956 9,454 0.53 0.35
A4A-DI-3B-1 15,501 11,619 3,882 0.75 0.36
A4-DI-3C 4,043 2,466 1,576 0.67 0.09
A3-DI-2A 14,879 9,729 5,150 0.69 0.34
A2-DI-2A 18,636 12,394 6,242 0.70 0.43
Al-DI-3C(EX) 16,830 10,095 6,735 0.66 0.39
B2-DI-3B(EX) 6,661 5,454 1,206 0.79 0.15
Cl-DI-3C(EX) 21,976 16,051 5,924 0.74 0.50
D2-DI-3B(EX) 21,967 14,190 7,777 0.69 0.50
D1-DI-3B(EX) 9,721 6,381 3,340 0.69 0.22
E3 4,651 1,411 3,239 0.48 0.11
E2 3,839 1,834 2,005 0.59 0.09
E1 4,988 2,227 2,761 0.57 0.11
F3 2,704 2,091 614 0.76 1 0.06
F2 2,932 2,099 833 0.73 0.07
F1 5,519 4,190 1,329 0.76 0.13
HTC AREA C TOWNHOMES BLOCK 2
LD-204 Stormwater Inlet Computations Inlets on Grade Only Sag Inlets Only
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1 2 3 4 5 6 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
ft) sf) ac) in/hr) cfs) cfs) cfs) I (ft) ft) cfs) cfs) ft) ft) ft)
A8 DI-7 3.5 17001 0.39 0.63 0.25 4.0 0.99 0.00 0.99 0.015 0.03 0.02 0.08 0.10 0.5 0.20 2.08
6.5 1.60 0.00 1.60 0.015 0.03 0.02 0.08 0.14 0.5 0.27 2.21
A6 DI-2A 10 38914 0.89 0.76 0.68 4.0 2.70 0.00 2.70 0.015 0.03 0.02 0.08 6.27 0.25 100.0% 2.70 0.00
6.5 4.39 0.00 4.39 0.015 0.03 0.02 0.08 8.14 0.29 96.8°% 4.25 0.14
A5 DI-7 3.5 15410 0.35 0.53 0.19 4.0 0.75 0.00 0.75 0.015 0.09 0.5 0.17 6.03
6.5 1.22 0.00 1.22 0.015 0.12 0.5 0.24 7.66
MA D1-313 10 FT 15501 0.36 0.75 0.27 4.0 1.07 0.00 1.07 0.015 0.03 0.02 0.08 1.96 0.17 98.8% 1.05 0.01
6.5 1.73 0.00 1.73 0.015 0.03 0.02 0.08 3.40 0.19 91.1 °% 1.58 0.15
A4 DI-3C 6 FT 4043 0.09 0.67 0.06 4.0 0.25 0.01 0.26 0.015 0.03 0.02 0.08 0.05 0.5 0.10 0.63
6.5 0.40 0.15 0.56 0.015 0.03 0.02 0.08 0.09 0.5 0.17 1.04
A3 DI-2A 8 FT 14879 0.34 0.69 0.24 4.0 0.95 0.00 0.95 0.015 0.03 0.02 0.08 1.97 0.17 100.0% 0.95 0.00
6.5 1.54 0.14 1.68 0.015 0.03 0.02 0.08 3.71 0.20 100.0% 1.68 0.00
A2 DI-2A 8 FT 18636 0.43 0.70 0.30 4.0 1.20 0.00 1.20 0.015 0.03 0.02 0.08 2.61 0.18 100.0% 1.20 0.00
6.5 1.94 0.00 1.94 0.015 0.03 0.02 0.08 4.19 0.21 100.0% 1.94 0.00
Al
REPLACE
EX)
DI-3C 10 FT 16830 0.39 0.66 0.25 4.0 1.02 0.00 1.02 0.015 0.03 0.02 0.08 2.34 0.17 100.0% 1.02 0.00
6.5 1.66 0.00 1.66 0.015 0.03 0.02 0.08 3.93 0.20 96.2°% 1.59 0.06
131 (EX) D1-313 6 FT 6661 0.15 0.79 0.12 4.0 0.48 0.00 0.48 0.015 0.03 0.02 0.08 1.57 0.16 97.4°% 0.47 0.01
6.5 0.79 0.00 0.79 0.015 0.03 0.02 0.08 1.89 0.16 88.8°% 0.70 0.09
C1
REPLACE
EX)
DI-3C 10 FT 21976 0.50 0.74 0.37 4.0 1.49 0.00 1.49 0.015 0.03 0.02 0.08 5.43 0.23 100.0% 1.49 0.00
6.5 2.42 0.00 2.42 0.015 0.03 0.02 0.08 7.21 0.27 97.5°% 2.36 0.06
D2 (EX) D1-313 8 FT 21967 0.50 0.69 0.35 4.0 1.39 0.00 1.39 0.015 0.03 0.02 0.08 5.19 0.23 99.7°% 1.38 0.00
6.5 2.25 0.00 2.25 0.015 0.03 0.02 0.08 6.93 0.26 90.4°% 2.04 0.22
D1 (EX) D1-313 6 FT 9721 0.22 0.69 0.15 4.0 0.62 0.00 0.62 0.015 0.03 0.02 0.08 2.50 0.18 100.0% 0.62 0.00
6.5 1.01 0.22 1.22 0.015 0.03 0.02 0.08 4.74 0.22 93.2°% 1.14 0.08
LD-229 Storm Drain Design Computations
HTC AREA C TOWNHOMES BLOCK 2
From
Structure
To
Structure
Catch.
Area
ac
Runoff
Coef
Increment
AC
Accum.
AC
Total
TOC
min
Total
Intensity
in/hr
Total
Flow
cfs
Up
Invert
Elev.
Down
Invert
Elev.
Pipe
Length
ft
Invert
Slope
Pipe
Diameter
inIds)
Pipe
Capacity
Velocity
ft/s)
Flow time
Increment
min
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
A8 A7 0.39 0.63 0.25 0.25 5.09 6.78 1.67 570.00 569.07 40.90 2.28% 15 10.6 6.3 0.11
A7 A6 0.25 0.25 5.00 6.81 1.68 568.87 568.56 16.05 1.93% 15 9.7 5.9 0.05
A6 A5 0.89 0.76 0.68 0.92 5.05 6.80 6.27 568.36 567.02 75.29 1.78% 15 9.3 8.2 0.15
A5 A4 0.35 0.53 0.19 1.11 5.20 6.75 7.50 566.82 566.05 77.36 1.00% 15 7.0 6.4 0.20
MA A4 0.36 0.75 0.27 0.27 5.00 6.81 1.82 573.00 572.34 24.48 2.70% 15 11.5 6.8 0.06
A4 A3 0.09 0.67 0.06 1.44 5.26 6.74 9.69 565.85 564.90 70.78 1.34% 18 13.2 8.1 0.14
A3 A2 1 0.34 0.69 0.24 1.68 1 5.41 6.70 11.22 1 564.70 564.33 33.21 1.11% 1 18 12.0 7.7 1 0.07
A2 At 0.43 0.70 0.30 1.97 5.48 6.68 13.18 564.13 563.81 22.88 1.40% 18 13.5 8.7 0.04
At AO 0.39 0.66 0.25 2.23 5.52 6.66 14.86 563.61 562.95 45.38 1.45% 18 16.4 10.5 0.07
B7 BO 0.15 0.79 0.12 0.12 5.00 6.81 0.82 562.00 560.58 35.06 4.05% 24 49.3 5.9 0.10
C1 CO 0.50 0.74 0.37 0.37 5.00 6.81 2.54 595.02 593.15 66.78 2.80% 15 11.7 7.6 0.15
D2 D1 0.50 0.69 0.35 0.35 5.00 6.81 2.36 577.69 565.83 142.81 8.30% 15 32.8 10.8 0.22
D1 DO 0.22 0.69 0.15 0.50 5.22 6.75 3.38 565.76 547.70 356.62 5.06% 18 25.6 10.0 0.59
E3 E2 0.11 0.48 0.05 0.05 5.00 6.81 0.35 580.00 578.00 47.49 4.21% 6 1.2 5.5 0.15
E2 E1 0.09 0.59 0.05 0.10 5.15 6.77 0.70 577.80 574.00 64.53 5.89% 6 1.5 7.4 0.15
E1 A5 0.11 0.00 0.00 0.10 5.15 6.77 0.70 573.00 571.40 29.64 5.40% 6 1.4 7.2 0.07
F3 F2 0.06 0.76 0.05 0.05 5.00 6.81 0.32 581.00 579.20 97.73 1.84% 6 0.8 3.9 0.41
F2 F1 0.07 0.73 0.05 0.10 5.41 6.69 0.65 579.00 573.20 109.74 5.29% 6 1.4 7.0 0.26
F1 A8 0.13 1 0.76 1 0.10 0.19 5.26 1 6.74 1.29 573.00 1 571.00 1 42.54 4.70% 6 1 1.3 7.7 0.09
SHIMP ENGINEERING, P.C.
Design Focused Engineering
Block III
Open Space Exhibit
Inlets Drainage Area Map
Structure Drainage Area Summary
VDOT LD-204
VDOT LD-229
HTC AREA C TOWNHOMES BLOCK 3
Inlet Drainage Area Summary
Impervious C 10.9
Pervious C 10.3
To Inlet Area Impervious Turf C A
A2 56,901 13,703 43,198 0.44 1.31
AO 4,836 1,600 3,236 0.50 0.11
B1 1 21,595 1 14,964 1 6,631 1 0.72 1 0.50
LOCKWOOD DRIVE
58' PUBLIC R/W)
DB 3414 PG 273
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PUBLIC ETURF ON
SITE AREA CALCULATION
DISCRIPTION SF
AC IMPERVIOUS 24,
173.33 0.55 24.6 TURF 73,
982.70 1.70 75.4 TOTAL 98,
156.02 2.25 100.0 STORM MASTER
PLAN ALLOWABLE IMPERVIOUS = 85%
N42'02'
52" E 48'32'52"E 201.25'
N40'S8'17"E10.45' 3 N
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LLC ZONE: NMD
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VIS6P.C. ENGRYEERa'G-
L ADPLANWa'G-PROPECTHANAGEWAT 4 HTC
AREA
C Townhomes BLOCK II OPEN SPACE
EXHIBIT REVISION DATE:
10/05/2020 BERKMAR DRIVE
STATE ROUTE
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8.50'
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HTC AREA C Townhomes BLOCK III
Inlets Drainage Area Map
REVISION DATE: 10/05/2020
LEGEND
m 1 1 . INLET DRAINAGE AREA
YARD DRAIN DRAINAGE
AREA DIVIDE
mTURF AREA
I
i1 ,
1
50 0 50 100 150
JIcWe:
1'=50'
HTC AREA C TOWNHOMES BLOCK 3
Inlet Drainage Area Summary
Impervious C 10.9
Pervious C 10.3
To Inlet Area Impervious Turf C A
A2 56,901 13,703 43,198 0.44 1.31
AO 4,836 1,600 3,236 0.50 0.11
B1 1 21,595 1 14,964 1 6,631 1 0.72 1 0.50
HTC AREA C TOWNHOMES BLOCK 3
LD-204 Stormwater Inlet Computations Inlets on Grade Only Sag Inlets Only
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1 2 3 4 5 6 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
ft) sf) ac) in/hr) cfs) cfs) cfs) P) P) P) ft ft) cfs) cfs) ft) ft ft)
A2 D1-313 10 56901 1.31 0.44 0.58 4.0 2.32 0.00 2.32 0.015 0.03 0.02 0.08 0.18 0.5 0.35 7.60
6.5 3.77 0.00 3.77 0.015 0.03 0.02 0.08 0.24 0.5 0.49 9.64
AO Ex. D1-313 8 4836 0.11 0.50 0.06 4.0 0.22 0.00 0.22 0.015 0.03 0.02 0.08 1.52 0.16 100.0% 0.22 0.00
6.5 0.36 0.14 0.50 0.015 0.03 0.02 0.08 2.27 0.17 100.0% 0.50 0.00
131 D1-313 8 21595 0.50 0.72 0.35 4.0 1.42 0.00 1.42 0.015 0.03 0.02 0.08 6.02 0.25 100.0% 1.42 0.00
6.5 2.31 0.00 2.31 0.015 0.03 0.02 0.08 7.87 0.28 93.8% 2.16 0.14
LD-229 Storm Drain Design Computations
HTC AREA C TOWNHOMES BLOCK 3
From
Structure
To
Structure
Catch.
Area
ac
Runoff
Coot
Increment
AC
Accum.
AC
Total
TOC
min
Total
Intensity
in/hr
Total
Flow
cfs
Up
Invert
Elev.
Down
Invert
Elev.
Pipe
Length
ft
Invert
Slope
Pipe
Diameter
in)
Pipe
Capacity
cfs)
Velocity
fus)
Flow time
Increment
min
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
A2 Al 1.31 0.44 0.58 0.58 5.00 6.81 3.95 578.00 576.00 96.68 2.07% 15 10.1 7.7 0.21
Al AO 0.11 0.50 0.06 0.06 5.21 6.75 0.37 575.19 572.12 34.62 8.87% 24 73.0 6.1 0.10
B1 Al 0.50 0.72 0.35 i 0.35 i 5.00 6.81 2.42 1 577.00 576.00 17.35 1 5.76% 15 16.8 9.7 0.03
SHIMP ENGINEERING, P.C.
Design Focused Engineering
Independent Reports:
Excerpt from NRCS Soils Report
NOAA Precipitation Report
I
i
Soil Map
The soil map section includes the soil map for the defined area of interest, a list of
soil map units on the map and extent of each map unit, and cartographic symbols
displayed on the map. Also presented are various metadata about data used to
produce the map, and a description of each soil map unit.
S
r'
y
i /
r _ `v
MAPLEGEND
Area of Interest (AOQ
O Area of Interest (AOI)
Solis
Soil Map Unit Polygons
N Soil Map Unit Lines
Soil Map Unit Points
Special Point Features
V Blowout
Borrow Pit
Clay Spot
O Closed Depression
Gravel Pit
Gravelly Spot
O Landfill
A. Lava Flow
Marsh or swamp
Mine or Quarry
O Miscellaneous Water
O Perennial Water
y Rock Outcrop
Saline Spot
Sandy Spot
Severely Eroded Spot
Q Sinkhole
Slide or Slip
J, Sodic Spot
Custom Soil Resource Report
MAP INFORMATION
g Spoil Area The soil surveys that comprise your AOI were mapped at
1:15,800.
o Stony Spot
W Very Stony Spot Warning: Soil Map may not be valid at this scale.
wet Spot
Enlargement of maps beyond the scale of mapping can causeOther
misunderstanding of the detail of mapping and accuracy of soil
Special Line Features line placement. The maps do not show the small areas of
contrasting soils that could have been shown at a more detailed
Water Features scale.
Streams and Canals
Transportation Please rely on the bar scale on each map sheet for map
ry Rails measurements.
N Interstate Highways
Source of Map: Natural Resources Conservation Service
ti US Routes Web Soil Survey URL:
Coordinate System: Web Mercator (EPSG:3857)
Major Roads
Local Roads Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
Background distance and area. A projection that preserves area, such as the
Aerial Photography Albers equal-area conic projection, should be used if more
accurate calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as
of the version date(s) listed below.
Soil Survey Area: Albemarle County, Virginia
Survey Area Data: Version 14, Jun 3, 2020
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: May 20, 2019—Aug
1, 2019
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
imagery displayed on these maps. As a result, some minor
shifting of map unit boundaries may be evident.
10
Custom Soil Resource Report
Map Unit Legend
Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI
27C Elioak loam, 7 to 15 percent 2.4 8.7%
slopes
28C3 Elioak Gay loam, 7 to 15 0.2 0.9%
percent slopes, severely
eroded
47C Philomont sandy loam, 7 to 15 6.0 22.1%
percent slopes
65B Fairview sandy loam, 2 to 7 10.6 38.9%
percent slopes
65C Fairview sandy loam, 7 to 15 4.0 14.5%
percent slopes
94B Toast sandy loam, 2 to 7 3.9 14.1%
percent slopes
94C Toast sandy loam, 7 to 15 0.2 0.7%
percent slopes
Totals for Area of Interest 27.3 100.08A
Map Unit Descriptions
The map units delineated on the detailed soil maps in a soil survey represent the
soils or miscellaneous areas in the survey area. The map unit descriptions, along
with the maps, can be used to determine the composition and properties of a unit.
A map unit delineation on a soil map represents an area dominated by one or more
major kinds of soil or miscellaneous areas. A map unit is identified and named
according to the taxonomic classification of the dominant soils. Within a taxonomic
class there are precisely defined limits for the properties of the soils. On the
landscape, however, the soils are natural phenomena, and they have the
characteristic variability of all natural phenomena. Thus, the range of some
observed properties may extend beyond the limits defined for a taxonomic class.
Areas of soils of a single taxonomic class rarely, if ever, can be mapped without
including areas of other taxonomic classes. Consequently, every map unit is made
up of the soils or miscellaneous areas for which it is named and some minor
components that belong to taxonomic classes other than those of the major soils.
Most minor soils have properties similar to those of the dominant soil or soils in the
map unit, and thus they do not affect use and management. These are called
noncentrasting, or similar, components. They may or may not be mentioned in a
particular map unit description. Other minor components, however, have properties
and behavioral characteristics divergent enough to affect use or to require different
management. These are called contrasting, or dissimilar, components. They
generally are in small areas and could not be mapped separately because of the
scale used. Some small areas of strongly contrasting soils or miscellaneous areas
are identified by a special symbol on the maps. If included in the database for a
given area, the contrasting minor components are identified in the map unit
11
Custom Soil Resource Report
descriptions along with some characteristics of each. A few areas of minor
components may not have been observed, and consequently they are not
mentioned in the descriptions, especially where the pattern was so complex that it
was impractical to make enough observations to identify all the soils and
miscellaneous areas on the landscape.
The presence of minor components in a map unit in no way diminishes the
usefulness or accuracy of the data. The objective of mapping is not to delineate
pure taxonomic classes but rather to separate the landscape into landforms or
landform segments that have similar use and management requirements. The
delineation of such segments on the map provides sufficient information for the
development of resource plans. If intensive use of small areas is planned, however,
onsite investigation is needed to define and locate the soils and miscellaneous
areas.
An identifying symbol precedes the map unit name in the map unit descriptions.
Each description includes general facts about the unit and gives important soil
properties and qualities.
Soils that have profiles that are almost alike make up a soil series. Except for
differences in texture of the surface layer, all the soils of a series have major
horizons that are similar in composition, thickness, and arrangement.
Soils of one series can differ in texture of the surface layer, slope, stoniness,
salinity, degree of erosion, and other characteristics that affect their use. On the
basis of such differences, a soil series is divided into soil phases. Most of the areas
shown on the detailed soil maps are phases of soil series. The name of a soil phase
commonly indicates a feature that affects use or management. For example, Alpha
silt loam, 0 to 2 percent slopes, is a phase of the Alpha series.
Some map units are made up of two or more major soils or miscellaneous areas.
These map units are complexes, associations, or undifferentiated groups.
A complex consists of two or more soils or miscellaneous areas in such an intricate
pattern or in such small areas that they cannot be shown separately on the maps.
The pattern and proportion of the soils or miscellaneous areas are somewhat similar
in all areas. Alpha -Beta complex, 0 to 6 percent slopes, is an example.
An association is made up of two or more geographically associated soils or
miscellaneous areas that are shown as one unit on the maps. Because of present
or anticipated uses of the map units in the survey area, it was not considered
practical or necessary to map the soils or miscellaneous areas separately. The
pattern and relative proportion of the soils or miscellaneous areas are somewhat
similar. Alpha -Beta association, 0 to 2 percent slopes, is an example.
An undifferentiated group is made up of two or more soils or miscellaneous areas
that could be mapped individually but are mapped as one unit because similar
interpretations can be made for use and management. The pattern and proportion
of the soils or miscellaneous areas in a mapped area are not uniform. An area can
be made up of only one of the major soils or miscellaneous areas, or it can be made
up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example.
Some surveys include miscellaneous areas. Such areas have little or no soil
material and support little or no vegetation. Rock outcrop is an example.
iv
Custom Soil Resource Report
Albemarle County, Virginia
27C—Elioak loam, 7 to 15 percent slopes
Map Unit Setting
National map unit symbol: kb8z
Elevation: 340 to 820 feet
Mean annual precipitation: 25 to 65 inches
Mean annual air temperature: 54 to 59 degrees F
Frost -free period: 195 to 231 days
Farmland classification: Farmland of statewide importance
Map Unit Composition
Elioak and similar soils: 80 percent
Estimates are based on observations,
Description of Elioak
descriptions, and transects of the mapunit.
Setting
Landform: Hillslopes
Landform position (two-dimensional): Summit
Landform position (three-dimensional): Interfluve
Down -slope shape: Convex
Across -slope shape: Convex
Parent material: Residuum weathered from mica schist
Typical profile
H1 - 0 to 8 inches: loam
H2 - 8 to 39 inches: silty clay
H3 - 39 to 79 inches: silt loam
Properties and qualities
Slope: 7 to 15 percent
Depth to restrictive feature: More than 80 inches
Drainage class: Well drained
Runoff class: Medium
Capacity of the most limiting layer to transmit water (Ksat)
0.20 to 1.98 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Available water capacity: Moderate (about 6.6 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 3e
Hydrologic Soil Group: B
Hydric soil rating: No
Moderately high to high
13
Custom Soil Resource Report
28C3—Elioak clay loam, 7 to 15 percent slopes, severely eroded
Map Unit Setting
National map unit symbol: kb91
Elevation: 330 to 710 feet
Mean annual precipitation: 25 to 65 inches
Mean annual air temperature: 54 to 59 degrees F
Frost -free period: 195 to 231 days
Farmland classification: Not prime farmland
Map Unit Composition
Elioak and similar soils: 80 percent
Estimates are based on observations,
Description of Elioak
descriptions, and transects of the mapunit.
Setting
Landform: Hillslopes
Landform position (two-dimensional): Summit
Landform position (three-dimensional): Interfluve
Down -slope shape: Convex
Across -slope shape: Convex
Parent material: Residuum weathered from mica schist
Typical profile
H1 - 0 to 8 inches: clay loam
H2 - 8 to 39 inches: silty clay
H3 - 39 to 79 inches: silt loam
Properties and qualities
Slope: 7 to 15 percent
Depth to restrictive feature: More than 80 inches
Drainage class: Well drained
Runoff class: Medium
Capacity of the most limiting layer to transmit water (Ksat)
0.20 to 1.98 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Available water capacity: Low (about 6.0 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 4e
Hydrologic Soil Group: B
Hydric soil rating: No
Moderately high to high
14
Custom Soil Resource Report
47C—Philomont sandy loam, 7 to 15 percent slopes
Map Unit Setting
National map unit symbol: 2v7j9
Elevation: 360 to 1,540 feet
Mean annual precipitation: 25 to 65 inches
Mean annual air temperature: 54 to 59 degrees F
Frost -free period: 195 to 231 days
Farmland classification: Not prime farmland
Map Unit Composition
Philomont and similar soils: 75 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Philomont
Setting
Landform: Hillslopes
Landform position (two-dimensional): Summit
Landform position (three-dimensional): Interfluve
Down -slope shape: Convex
Across -slope shape: Convex
Parent material: Residuum weathered from granite and gneiss
Typical profile
Ap - 0 to 5 inches: sandy loam
Bt - 5 to 79 inches: sandy loam
Properties and qualities
Slope: 7 to 15 percent
Depth to restrictive feature: More than 80 inches
Drainage class: Well drained
Runoff class: Low
Capacity of the most limiting layer to transmit water (Ksat): High to very high (5.95
to 19.98 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Available water capacity: Moderate (about 6.6 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 6e
Hydrologic Soil Group: A
Hydric soil rating: No
15
Custom Soil Resource Report
6513—Fairview sandy loam, 2 to 7 percent slopes
Map Unit Setting
National map unit symbol: 2v7jx
Elevation: 360 to 1,540 feet
Mean annual precipitation: 25 to 65 inches
Mean annual air temperature: 54 to 59 degrees F
Frost -free period: 195 to 231 days
Farmland classification: All areas are prime farmland
Map Unit Composition
Fairview and similar soils: 90 percent
Estimates are based on observations,
Description of Fairview
descriptions, and transects of the mapunit.
Setting
Landform: Interfluves
Landform position (two-dimensional): Summit
Landform position (three-dimensional): Interfluve
Down -slope shape: Convex
Across -slope shape: Convex
Parent material: Residuum weathered from granite and gneiss
Typical profile
Ap - 0 to 6 inches: sandy loam
Bt - 6 to 32 inches: clay
C - 32 to 79 inches: sandy clay loam
Properties and qualities
Slope: 2 to 7 percent
Depth to restrictive feature: More than 80 inches
Drainage class: Well drained
Runoff class: Medium
Capacity of the most limiting layer to transmit water (Ksat)
0.57 to 1.98 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Available water capacity: Moderate (about 7.6 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 2e
Hydrologic Soil Group: B
Hydric soil rating: No
Moderately high to high
it.
Custom Soil Resource Report
65C—Fairview sandy loam, 7 to 15 percent slopes
Map Unit Setting
National map unit symbol: 2v7jy
Elevation: 360 to 1,540 feet
Mean annual precipitation: 25 to 65 inches
Mean annual air temperature: 54 to 59 degrees F
Frost -free period: 195 to 231 days
Farmland classification: Farmland of statewide importance
Map Unit Composition
Fairview and similar soils: 90 percent
Estimates are based on observations,
Description of Fairview
descriptions, and transects of the mapunit.
Setting
Landform: Interfluves
Landform position (two-dimensional): Backslope
Landform position (three-dimensional): Nose slope
Down -slope shape: Convex
Across -slope shape: Convex
Parent material: Residuum weathered from granite and gneiss
Typical profile
Ap - 0 to 6 inches: sandy loam
Bt - 6 to 32 inches: clay
C - 32 to 79 inches: sandy clay loam
Properties and qualities
Slope: 7 to 15 percent
Depth to restrictive feature: More than 80 inches
Drainage class: Well drained
Runoff class: Medium
Capacity of the most limiting layer to transmit water (Ksat)
0.57 to 1.98 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Available water capacity: Moderate (about 7.6 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 4e
Hydrologic Soil Group: B
Hydric soil rating: No
Moderately high to high
IVA
Custom Soil Resource Report
9413—Toast sandy loam, 2 to 7 percent slopes
Map Unit Setting
National map unit symbol: 2v7k8
Elevation: 360 to 1,540 feet
Mean annual precipitation: 25 to 65 inches
Mean annual air temperature: 54 to 59 degrees F
Frost -free period: 195 to 231 days
Farmland classification: All areas are prime farmland
Map Unit Composition
Toast and similar soils: 90 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Toast
Setting
Landform: I nterfluves
Landform position (two-dimensional): Summit
Landform position (three-dimensional): Interfluve
Down -slope shape: Convex
Across -slope shape: Convex
Parent material: Residuum weathered from granite and gneiss
Typical profile
Ap - 0 to 7 inches: sandy loam
BA - 7 to 11 inches: sandy clay loam
Bt - 11 to 30 inches: clay
C - 30 to 60 inches: sandy clay loam
Properties and qualities
Slope: 2 to 7 percent
Depth to restrictive feature: More than 80 inches
Drainage class: Well drained
Runoff class: Medium
Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high
0.57 to 1.98 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Available water capacity: Moderate (about 8.0 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 2e
Hydrologic Soil Group: B
Hydric soil rating: No
WV
Custom Soil Resource Report
94C—Toast sandy loam, 7 to 15 percent slopes
Map Unit Setting
National map unit symbol: 2v7k9
Elevation: 360 to 1,540 feet
Mean annual precipitation: 25 to 65 inches
Mean annual air temperature: 54 to 59 degrees F
Frost -free period: 195 to 231 days
Farmland classification: Farmland of statewide importance
Map Unit Composition
Toast and similar soils: 90 percent
Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Toast
Setting
Landform: Interfluves
Landform position (two-dimensional): Backslope
Landform position (three-dimensional): Interfluve
Down -slope shape: Convex
Across -slope shape: Convex
Parent material: Residuum weathered from granite and gneiss
Typical profile
Ap - 0 to 7 inches: sandy loam
BA - 7 to 11 inches: sandy clay loam
Bt - 11 to 30 inches: clay
C - 30 to 60 inches: sandy clay loam
Properties and qualities
Slope: 7 to 15 percent
Depth to restrictive feature: More than 80 inches
Drainage class: Well drained
Runoff class: Medium
Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high
0.57 to 1.98 in/hr)
Depth to water table: More than 80 inches
Frequency of flooding: None
Frequency of ponding: None
Available water capacity: Moderate (about 8.0 inches)
Interpretive groups
Land capability classification (irrigated): None specified
Land capability classification (nonirrigated): 4e
Hydrologic Soil Group: B
Hydric soil rating: No
19
8/27/2020 Precipitation Frequency Data Server
NOAA Atlas 14, Volume 2, Version 3
Location name: Charlottesville, Virginia, USA* ei '1.
Latitude: 38.1307°, Longitude:-78.44190
Elevation: 591.85 ft**
a
source: ESRI Maps
source: USGS
POINT PRECIPITATION FREQUENCY ESTIMATES
G.M. Bonnin, D. Martin, B. Lin, T. Parzybok, M.Yekta, and D. Riley
NOAA, National Weather Service, Silver Spring, Maryland
PF tabular I PF graphical I Maps & aerials
PF tabular
PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches)1
Average recurrence interval (years)
1 2 5 10 25 50 100 200 500 1000
0.348 0.416 0.489 0.550 0.621 0.676 0.728 0.778 0.839 0.888
5-min
0.315-0.386) 0.376-0.461) 0.441-0.541) 0.495-0.608) 0.556-0.684) 0.602-0.744) 0.645-0.802) 0.684-0.857) 0.729-0.927) 0.765-0.985)
0.556 0.666 0.783 0.880 0.989 1.08 1.16 1.23 1.33 1.40
10-min 0.503-0.617) 0.601-0.737) 0.706-0.866) 0.792-0.972) 0.886-1.09) 0.959-1.19) 1.02-1.27 ) 1.08-1.36) 11 1.15-1.47) 1.21-1.55)
0.696 0.837 0.991 1.11 1.25 1.36 1.46 1.56 1.67 1.76
15-min 0.628-0.771) 0.756-0.927) 0.893-1.10) 1 (1.00-1.23) 1 (1.12-1.38) 1 (1.21-1.50) 1 (1.30-1.61) 1 (1.37-1.71) 1 (1.45-1.85) 1 (1.51-1.95)
0.954 1.16 1.41 1.61 1.86 2.05 2.24 2.42 2.66 2.84
30-min 0.861-1.06) 1 (1.04-1.28) 1 (1.27-1.56) 1 (1.45-1.78) 1 (1.66-2.05) 1.83-2.26) 1.98 2.47) 2.13-2.67) 2.31-2.94) 2.45-3.15)
1.19 1.45 1.81 2.10 2.47 2.78 3.09 3.40 3.81 4.15
60-min 1.07-1.32) 1 (1.31-1.61) 1 (1.63-2.00) 1 (1.89-2.32) 1 (2.21-2.73) 2.48-3.06) 1 (2.73-3.40) 1 (2.99-3.74) 3.31-4.21 3.58-4.60)
1.43 1.74 2.17 2.56 3.05 3.47 3.89 4.35 4.98 5.51
2-hr
1.27-1.62) 1.54-1.96) 1.93-2.46) 2.26-2.88) 2.68-3.43) 3.03-3.90) 3.38-4.38) 3.74-4.88) 4.24-5.60) 4.64-6.22)
1.56 1.90 2.38 2.79 3.33 3.79 4.26 4.76 5.46 6.06
3-hr 1 .38-1.79) 1 (1.67-2.17) 1 (2.09-2.71) 1 (2.44-3.17) 1 (2.90-3.78) 3.28-4.30) 3.67-4.84) 1 (4.07-5.41) 1 (4.61-6.21) 5.06-6.90)
1.99 2.40 2-.9-9-IF 3.52 4.23 4.86 F 6.23 7.25 8.16
6-hr 1.77-2.26) 1 (2.13-2.73) 1 (2.64-3.39) 1 (3.09-3.99) 1 (3.69-4.79) 4.21-5.48) 4.736.23) 5.29-7.04) 6.06-8.21) 6.72-9.25)
2.49 3.01 3.75 4.44 5.40 6.26 7.20 8.23 9.76 11.1
12-hr 2.21-2.85) 1 (2.66-3.44) 1 (3.31-4.29) 1 (3.90-5.06) 1 (4.70-6.14) 1 (5.40-7.11) 6.13-8.16) 6.91-9.33) 8.03-11.1) 9.02-12.7)
hftps://hdsc.rms.noaa.govlhdscfpfdslpfds_rrintpage.html?lat=38.1307&Ion=-78.4419&data=depth&units=english&series=pds 1/6
8/27/2020 Precipitation Frequency Data Server
24-hr 2.98 11
2 .67-3.35)
3.60 11
3.23-4.05)
4.60 11
4.11-5.17)
5.43 11
4.85-6.10)
6.67 11
5.91-7.47)
7.73 11
6.80-8.64)
8.90 11
7.76-9.93)
10.2
8.80-11.3)
12.1
10.3-13.5)
13.8
11.5-15.3)
2-day
3.51 4.25 5.40 6.34 7.71 8.86 10.1 11.5 13.4 15.1
3.16-3.92) 3.83-4.75) 4.85-6.03) 5.68-7.07) 6.86-8.58) 7.83-9.84) 8.86-11.2) 9.97-12.7) 11.5-15.0) 12.8-16.8)
3.73 4.52 5.74 6.75 8.20 9.42 10.7 12.2 14.2 16.0
3-day 3.39-4.14) 4.10-5.02) 5.20-6.37) 6.09-7.47) 7.36-9.06) 8.40-10.4) 9.50-11.9) 10.7-13.4) 12.4-15.8) 13.7-17.7)
3.96 4.80 6.09 7.15 8.68 9.97 11.4 12.9 15.0 16.9
4-day 3.62-4.37) 4.38-5.29) 5.55-6.71) 6.50-7.86) 7.87-9.55) 8.98-11.0) 10.2-12.5 ) 11.4-14.1) 11 13.2-16.6) 14.6-18.6)
4.60 5.54 6.93 8.06 9.69 11.0 12.5 14.1 16.3 18.2
7-day 4.22-5.05) 5.08-6.07) 6.33-7.59) 7.35-8.83) 8.80-10.6) 9.97-12.1) 11.2-13.7 ) 12.5-15.4) 11 14.3-17.9) 15.8-20.0)
5.23 6.27 7.74 8.93 10.6 12.0 F 15.0 17.1 18.9
10-day 4 .81-5.68) 1 (5.77-6.81) 1 (7.11-8.40) 1 (8.19-9.69) 1 (9.69-11.5) 1 (10.9-13.0) 12.1-14.6) 13.4-16.2) 11 15.2-18.6) 1 (16.6-20.6)
6.87 8.19 IF 9.89 11.2 13.0 14.5 15.9 17.4 19.4 21.0
20-day 6.41-7.38) 1 (7.65-8.80) 1 (9.23-10.6) 1 (10.5-12.1) 1 (12.1-14.0) 1 (13.4-15.5) 1 (14.7-17.1) 1 (16.0-18.7) 1 (17.7-20.9) 1 (19.0-22.7)
8.43 9.99 11.8 13.2 15.0 16.4 F 19.1 20.8 22.1
30-day 7 .92-9.00) 1 (9.39-10.7) 1 (11.1-12.6) 1 (12.4-14.1) 1 (14.0-16.0) 1 (15.3-17.5) 16.518.9) 17.6-20.4) 11 19.1-22.3) 1 (20.3-23.7)
10.5 12.4 14.5 16.1 18.1 19.6 21.0 22.4 24.2 25.5
45-day 9.92-11.2) 1 (11.7-13.2) 1 (13.7-15.4) 1 (15.1-17.0) 1 (17.0-19.2) 1 (18.4-20.8) 1 (19.7-22.3) 1 (20.9-23.8) 1 (22.4-25.8) 1 (23.5-27.2)
12.4 14.5 16.8 18.4 20.6 22.1 23.6 25.0 26.8 28.1
60-day 117-13.1) 13.7-15.4) 15.917.7) 17.4-19.5) 19.4-21.7) 20.8-23.4) 22.2-25.0) 23.5-26.5) 25.0-28.4) 26.2-29.9)
Precipitation frequency (PF) estimates in this table are based on frequency analysis of partial duration series (PDS).
Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval. The probability that precipitation frequency estimates (for
a given duration and average recurrence interval) will be greater than the upper bound (or less than the lower bound) is 5%. Estimates at upper bounds are not
checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values.
Please refer to NOAA Atlas 14 document for more information.
Back to Top
PF graphical
PDS-based depth -duration -frequency (DDF) curves
Latitude: 38.13070, Longitude:-78.44190
25........'......'.....'.................
Average recurrence
mterval
years)
hftps://hdsc.rms.noaa.govlhdsc/pfdslpfds_rrintpage.html?lat=38.1307&Ion=-78.4419&data=depth&units=english&series=pds 2/6